It's dangerous to go alone, take this!
I was speaking of the Debian "full archive" 21-DVD sets: https://www.shoplinuxonline.com/debian-full.html
But I don't know about how they package it, so it might not be a "box set" as you describe.
Last time I used Elementary OS, it was great if you were only using the official apps, with insane degrees of polish, but things like LibreOffice were surprisingly hard to configure the way I wanted. That was a while ago, though.
There was still Wine, and PlayOnLinux helped further, but when I looked for a game I wanted to play on WineDB, there was no guarantee it even had an entry, and if it wasn't listed as "platinum", the chance of you experiencing any reported issue was very high.
Not to mention, playing Steam games that weren't native was an impossibility.
Thankfully I was more of a console gamer at the time, and I got a lot of enjoyment out of the few games that received Linux ports - like Team Fortress 2!
Debian needs a better installer. It'd be awesome if it had something more akin to Fedora/RHEL's Anaconda, or even just made Calamares the default (so long as it didn't install every single locale available like their live inages currently do).
Another commenter suggested Tiny Core Linux and DSL2024, which are indeed as light as it gets, but you might find yourself limited in what you can do with them, and it's not necessary for those specs.
The next step up would be Q4OS Trinity and antiX. You should be able to get the Spotify app and your preferred web server running on either of those.
Debian 12 ships with the non-free-firmware repo enabled by default, including firmware-iwlwifi, but a few Broadcom cards, and maybe others, still require software in non-free if I recall correctly
I'm aware of FreeTube and PlasmaTube, which IIRC both require an Invidious instance. There was something called SMTube in the past, not sure if it still exists.
Nothing I'm aware of has both desktop and mobile version, but if anything there are more options for mobile YouTube clients; try NewPipe or Clipious.
Edit: SMTube does still exist. It does not require Invidious, but it does use tonvid.com.
Startendo DS (Dual Screen) Nine
Super glad it's still in production despite all the bullshit with Paramount+. Though I still wonder where it will be published...
Assuming you mean the Beelink S12 (which is the first thing that comes up in a search for "n100 mini pc"), that's quite similar to my own computer specs, which can run just about any distro, with enough resources to spare for a VM or two. I don't think it's necessary to go really lightweight or pick something special. If there's a distro you're already familiar with and know you can do all of those things on, install that.
If you like Garuda, you could always try a different Arch spin which is lighter out of the box, like CachyOS or EndeavourOS.